This invention relates generally to manifold valve assemblies to selectively control the passage of fluid through a group of ports, and more particularly to a valve assembly having a row of click-type push-button actuators, one for each valve, to facilitate the selection of the valves and to indicate their operating status.
Many industrial, commercial and medical applications exist for a multi-port valve assembly adapted to direct an incoming fluid into one or more selected ports and to block flow into all other ports. For example, in intravenously supplying a saline or other solution to a patient by means of catheters inserted at various points in the vascular system of the patient or in a venous pressure measuring instrument such as that disclosed in the Miller et al. U.S. Pat. No. 3,807,389, in which fluid must be directed in various paths, the need exists for a selective valve mechanism capable of carrying out the desired procedures.
To this end, the common practice is to employ a multiposition stopcock whose structure is such that each setting thereof brings about a fluid connection between two or more lines in a network thereof while blocking all other lines. Because in such multi-position valves there is usually a single rotatable or adjustable valve member which cooperates with a group of ports that are interconnected or blocked, depending on the operative position of this member, the dimensional tolerances of the valve must be stringent. This factor makes such valves difficult and expensive to manufacture.
Moreover, such multi-position valves are relatively hard to operate. When the valve actuator is to be shifted or turned to a particular setting by one hand, the other hand of the operator must be used to grasp and steady the valve body. The operator must then exercise care in setting the valve actuator to the appropriate position for the desired line connections.
But apart from these practical limitations is the fact that conventional multi-position valves provide no positive indication of their operating status. Though an operator conversant with the valve and its port connections should know its status, this is subject to human error. For example, if, say, at position 3 of a particular multi-position valve, an input line is connected to the first output port of a group of four ports, all others then being blocked, and at position 4, the input line is connected to the second and fourth ports, all others then being blocked, these line connections are not evident merely from the setting of the valve actuator; for the operator must be informed as to the relationship of each setting to the line connections. Inasmuch as the operator, in the case of a medical application for the valve assembly, is generally a nurse with many other responsibilities, the likelihood of error is high.
Another factor that must be taken into account, particularly in medical and pharmaceutical uses, is the sterilizability of the valve; for contamination of the fluid being controlled must be avoided. When the valve is of the usual multi-position type having occluded surfaces, full and effective sterilization of all valve areas in contact with the fluid is very difficult to effect.
While various forms of manifold-type valves are known in the prior art provided with a row of valves which are separately and individually actuated, such manifold-type valves fail to satisfy the various requirements dictated by medical and other applications. Typical prior art patents disclosing manifold or gang type valve assemblies are those issued to Axelrod U.S. Pat. Nos. (3,459,221) and Stewart (3,552,436).